Apparatus for manufacturing a semiconductor device

ABSTRACT

In a semiconductor device manufacturing method, an etching mask ( 75   b ) having a predetermined opening pattern is formed on an etching target film ( 74 ) disposed on a target object. Then, an etching process is performed on the etching target film ( 74 ) through the opening pattern of the etching mask ( 75   b ) within a first process chamber, thereby forming a groove or hole ( 78   a ) in the etching target film. Then, the target object treated by the etching process is transferred from the first process chamber to a second process chamber, within a vacuum atmosphere. Then, a silylation process is performed on a side surface of the groove or hole ( 78   a ), which is an exposed portion of the etching target film ( 74 ), within the second process chamber.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a U.S. national phase application under 35 U.S.C. §371 ofInternational Application PCT/JP2005/011973 (not published in English),filed Jun. 29, 2005.

TECHNICAL FIELD

The present invention relates to a method of manufacturing asemiconductor device, and particularly to an improvement of a method offorming an interconnection groove or connection hole used in asemiconductor device. Such interconnection groove or connection hole isutilized in forming a multi-layer interconnection structure by use of,e.g., a single damascene method or dual damascene method.

BACKGROUND ART

In semiconductor device manufacturing processes, a dual damascene methodis frequently used for forming a multi-layer interconnection structure(for example, see Jpn. Pat. Appln. KOKAI Publication No. 2002-83869).FIG. 20 comprises sectional views schematically showing sequentiallyordered steps of a conventional process for forming an interconnectionstructure by use of a dual damascene method.

At first, for example, an interconnection layer 500, an inter-levelinsulating film 501, and an anti-reflective coating 502 are formed inthis order on a substrate. Further, a first resist film 503 is formed onthe surface of the multi-layer structure thus formed (FIG. 20, (a)).Then, patterning of the first resist film 503 is performed by aphotolithography technique to form a predetermined pattern (FIG. 20,(b)). In this patterning step, the first resist film 503 is subjected tolight exposure with a predetermined pattern, and the light-exposedportion is selectively removed by development. Subsequently, theanti-reflective coating 502 and inter-level insulating film 501 areetched by an etching process using the first resist film 503 as a mask.Consequently, a connection hole 504 is formed to extend from the surfaceof the multi-layer structure to the interconnection layer 500 (FIG. 20,(c)).

Thereafter, for example, the first resist film 503, which is notnecessary any more, is peeled off and removed by an ashing process (FIG.20, (d)). Then, a new second resist film 505 for forming aninterconnection groove is formed (FIG. 20, (e)). Then, patterning of thesecond resist film 505 is performed by a photolithography technique(FIG. 20, (f)). Then, parts of the anti-reflective coating 502 and theinter-level insulating film 501 are etched by an etching process usingthe second resist film 505 as a mask. Consequently, an interconnectiongroove 506 is formed to be connected to the connection hole 504 andwider than the connection hole 504 (FIG. 20, (g)). Then, the secondresist film 505, which is not necessary any more, is peeled off andremoved (FIG. 20, (h)). Then, the connection hole 504 andinterconnection groove 506 are filled with Cu material, so that a Cuinterconnection line (including an interconnection layer and a via-plug)507 is formed (FIG. 20, (i)).

In recent years, for interconnection structures of this kind, lowdielectric constant materials (Low-k materials) including alkyl groups,such as methyl groups, as end groups are used as the material of theinter-level insulating film 501. In this case, etching damage tends tobe caused to the inner surface portion of the connection hole 504 orinterconnection groove 506, which has been formed by etching theinter-level insulating film 501. Further, when the first resist film 503and second resist film 505 are removed after the etching process, theinner surface portion of the connection hole 504 or interconnectiongroove 506 is damaged. Due to this damage, the parasitic capacitancebetween interconnection lines is increased (due to an increase indielectric constant), so a signal delay occurs and electricalcharacteristics, such as insulation resistance, are deteriorated. Theseproblems bring about deterioration in the reliability of semiconductordevices, as circuit patterns used in semiconductor devices areincreasingly miniaturized and highly integrated.

DISCLOSURE OF INVENTION

An object of the present invention is to provide a method ofmanufacturing a semiconductor device with improved electricalcharacteristics and reliability.

According to a first aspect of the present invention, there is provideda semiconductor device manufacturing method comprising: forming anetching mask having a predetermined opening pattern on an etching targetfilm disposed on a target object; performing an etching process on theetching target film through the opening pattern of the etching maskwithin a first process chamber, thereby forming a groove or hole in theetching target film; transferring the target object treated by theetching process from the first process chamber to a second processchamber, within a vacuum atmosphere; and performing a silylation processon a side surface of the groove or hole, which is an exposed portion ofthe etching target film, within the second process chamber.

According to a second aspect of the present invention, there is provideda semiconductor device manufacturing method comprising: forming anetching mask having a predetermined opening pattern on an etching targetfilm disposed on a target object; performing an etching process on theetching target film through the opening pattern of the etching maskwithin a process chamber, thereby forming a groove or hole in theetching target film; and performing a silylation process on a sidesurface of the groove or hole, which is an exposed portion of theetching target film, within the process chamber.

According to a third aspect of the present invention, there is provideda semiconductor device manufacturing method comprising: forming anetching mask having a predetermined opening pattern on an etching targetfilm disposed on a target object; performing an etching process on theetching target film through the opening pattern of the etching mask,thereby forming a groove or hole in the etching target film; performingan ashing process on the etching mask after the etching process, therebyremoving the etching mask from the target object; and performing asilylation process on a side surface of the groove or hole, which is anexposed portion of the etching target film, after the ashing process.

According to a fourth aspect of the present invention, there is provideda semiconductor device manufacturing method comprising: forming anetching mask having a predetermined opening pattern on an etching targetfilm disposed on a target object; performing an etching process on theetching target film through the opening pattern of the etching mask,thereby forming a groove or hole in the etching target film; performinga cleaning process using a chemical solution on the target object afterthe etching process; and performing a silylation process on a sidesurface of the groove or hole, which is an exposed portion of theetching target film, after the cleaning process.

According to a fifth aspect of the present invention, there is provideda semiconductor device manufacturing method comprising: forming aninter-level insulating film on an etching stopper film disposed on atarget object; forming a groove or hole in the inter-level insulatingfilm to reach the etching stopper film; performing an etching process onthe etching stopper film through the groove or hole of the inter-levelinsulating film, thereby removing a portion of the etching stopper filmpresent at a bottom of the groove or hole; and performing a silylationprocess on a side surface of the groove or hole, which is an exposedportion of the inter-level insulating film, after the etching process.

According to a sixth aspect of the present invention, there is provideda semiconductor device manufacturing system comprising: a first processchamber configured to accommodate a target object that comprises anetching target film and an etching mask formed thereon and including apredetermined opening pattern; an etching mechanism configured toperform an etching process on the etching target film through theopening pattern of the etching mask within the first process chamber, soas to form a groove or hole in the etching target film; a second processchamber configured to accommodate the target object after the targetobject is processed in the first process chamber; a silylation mechanismconfigured to perform a silylation process on a side surface of thegroove or hole, which is an exposed portion of the etching target film,within the second process chamber; a vacuum transfer passage connectingthe first and second process chambers to each other; and a transfermechanism disposed in the vacuum transfer passage and configured totransfer the target object from the first process chamber to the secondprocess chamber.

According to a seventh aspect of the present invention, there isprovided a semiconductor device manufacturing system comprising: aprocess chamber configured to accommodate a target object that comprisesan etching target film and an etching mask formed thereon and includinga predetermined opening pattern; an etching mechanism configured toperform an etching process on the etching target film through theopening pattern of the etching mask within the process chamber, so as toform a groove or hole in the etching target film; and a silylationmechanism configured to perform a silylation process on a side surfaceof the groove or hole, which is an exposed portion of the etching targetfilm, within the process chamber.

According to an eighth aspect of the present invention, there isprovided a computer readable medium containing program instructions forexecution on a processor, which, when executed by the processor, cause asemiconductor device manufacturing system to execute the manufacturingmethod according to any one of the first to fifth aspects.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory view schematically showing the arrangement of awafer processing system;

FIG. 2 is a plan view schematically showing the structure of a cleaningapparatus;

FIG. 3 is a front view schematically showing the structure of thecleaning apparatus;

FIG. 4 is a back view schematically showing the structure of thecleaning apparatus;

FIG. 5 is a sectional view schematically showing a silylation unit(SCH);

FIG. 6 is a plan view schematically showing the structure of an etchingapparatus;

FIG. 7 is a flowchart showing a process for forming an interconnectionstructure by use of a single damascene method;

FIG. 8 comprises sectional views showing sequentially ordered steps ofthe process shown in FIG. 7;

FIG. 9A is a graph showing how the relationship between leakage currentand cumulative probability differs depending on the presence and absenceof a silylation process;

FIG. 9B is a graph showing how the relationship between voltage andleakage current differs depending on the presence and absence of asilylation process;

FIG. 10 is a flowchart showing a process for forming an interconnectionstructure by use of a dual damascene method;

FIG. 11 comprises sectional views showing sequentially ordered steps ofthe process shown in FIG. 10;

FIG. 12 is a flowchart showing another process for forming aninterconnection structure by use of a dual damascene method;

FIG. 13 comprises sectional views showing sequentially ordered steps ofthe process shown in FIG. 12;

FIG. 14 is a sectional view schematically showing the structure of anetching unit;

FIG. 15 comprises sectional views showing the surface structure of awafer obtained in steps of a process using the etching unit shown inFIG. 14;

FIG. 16A comprises sectional views showing a change in the shape of agroove caused by a hydrofluoric acid immersing process where the groovehas not been treated by a silylation process;

FIG. 16B comprises sectional views showing a change in the shape of agroove caused by a hydrofluoric acid immersing process where the groovehas been treated by a silylation process;

FIG. 17A is a side view showing a step of processing a test sample formeasuring dielectric constant, leakage current density, and moisturedesorption amount;

FIG. 17B is a side view showing a test sample for measuring dielectricconstant, leakage current density, and moisture desorption amount;

FIG. 18 is a graph showing how the moisture desorption amount changesdepending on the presence and absence of a silylation process and thetype of silylation agent;

FIG. 19A is a view showing a test sample before a corrosion resistancetest using immersion in diluted hydrofluoric acid;

FIG. 19B is a view showing the test sample after the corrosionresistance test using immersion in diluted hydrofluoric acid; and

FIG. 20 comprises sectional views schematically showing sequentiallyordered steps of a conventional process for forming an interconnectionstructure by use of a dual damascene method.

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiments of the present invention will now be described withreference to the accompanying drawings. Hereinafter, the presentinvention is exemplified by a wafer processing system in which asemiconductor device is manufactured by a single damascene method ordual damascene method. Where an interconnection structure is formed by asingle damascene method or dual damascene method, an interconnectiongroove or connection hole (which will be referred to as “interconnectiongroove or the like” hereinafter) is utilized.

FIG. 1 is an explanatory view schematically showing the arrangement of awafer processing system. This wafer processing system includes a processsection 110 and a main control section 120. The process section 110includes an SOD (Spin On Dielectric) apparatus 101, a resistcoating/development apparatus 102, a light exposure apparatus 103, acleaning apparatus 104, an ashing apparatus 105, an etching apparatus106, a sputtering apparatus 107 used as a PVD apparatus, an electrolyticplating apparatus 108, and a CMP apparatus 109 used as a polishingapparatus. The main control section 120 includes a process controller111, a user interface 112, and a storage portion 113. The SOD apparatus101, sputtering apparatus 107, and electrolytic plating apparatus 108 ofthe process section 110 are film formation apparatuses. As a method fortransferring a wafer W between apparatuses in the process section 110, atransfer method by an operator and/or a transfer method by a transferunit (not shown) are used.

Each of the apparatuses in the process section 110 is connected to andcontrolled by the process controller 111 having a CPU. The processcontroller 111 is connected to a keyboard, the user interface 112, andthe storage portion 113. The keyboard is used for a process operator toinput commands for operating the apparatuses in the process section 110.The user interface 112 includes a display or the like used for showingvisualized images of the operational status of the apparatuses in theprocess section 110. The storage portion 113 stores recipes with controlprograms and process condition data recorded therein, for realizingvarious processes performed in the process section 110 under the controlof the process controller 111.

A required recipe is retrieved from the storage portion 113 and executedby the process controller 111 in accordance with an instruction or thelike input through the user interface 112. Consequently, each of variouspredetermined processes is performed in the process section 110 underthe control of the process controller 111. Recipes may be stored in areadable storage medium, such as a CD-ROM, hard disk, flexible disk, ornonvolatile memory. Further, recipes may be utilized on-line, while itis transmitted among the respective apparatuses in the process section110, or transmitted from an external apparatus through, e.g., adedicated line, as needed.

Each of the apparatuses in the process section 110 may be provided withand controlled by its own control section including a processcontroller, a user interface, and a storage portion. This arrangementcan be adopted in place of the global control by the main controlsection 120, or along with the global control by the main controlsection 120,

The SOD apparatus 101 is used to apply a chemical solution onto a waferW to form an inter-level insulating film formed of, e.g., a Low-k film,or an etching stopper film by a spin coating method. The SOD apparatus101 includes a spin coater unit and a heat processing unit to perform aheat process on a wafer W with a coating film formed thereon (althoughthe structure thereof is not shown in detail). In the case of a waferprocessing system, a CVD apparatus may be used to form an insulatingfilm on a wafer W by a chemical vapor deposition (CVD) method, in placeof the SOD apparatus 101.

The resist coating/development apparatus 102 is used to form a resistfilm used as an etching mask, and an anti-reflective coating. The resistcoating/development apparatus 102 includes a resist coating unit, adeveloping unit, and thermal processing units (although the structurethereof is not shown in detail). The resist coating unit is arranged toapply a resist liquid onto a wafer W to form a resist film by spincoating. The developing unit is arranged to perform a developmentprocess on a resist film which has been subjected to light exposure witha predetermined pattern in the light exposure apparatus 103. The thermalprocessing units are arranged to respectively perform thermal processeson a wafer W with a resist film formed thereon, a wafer W treated by alight exposure process, and a wafer W treated by a development process.

The light exposure apparatus 103 is used to subject a wafer W with aresist film formed thereon to light exposure with a predeterminedcircuit pattern. The cleaning apparatus 104 is arranged to perform acleaning process using purified water or a chemical solution, adenaturing process of polymer residues etc. remaining after an etchingprocess, and a recovery process of an inter-level insulating film fordamage due to etching, as described later in detail. The ashingapparatus 105 is arranged to perform an ashing process of a resist film,by use of, e.g., plasma.

The etching apparatus 106 is arranged to perform an etching process onan inter-level insulating film or the like formed on a wafer W, and arecovery process of an inter-level insulating film for damage due toetching. The etching process may be of a type using plasma or a typeusing a chemical solution. An etching using plasma will be describedlater, with reference to FIG. 6. The sputtering apparatus 107 is used toform, e.g., each of an anti-diffusion film and a Cu seed layer. Theelectrolytic plating apparatus 108 is arranged to embed Cu in aninterconnection groove having a Cu seed layer formed therein. The CMPapparatus 109 is arranged to perform a planarization process on asurface of an interconnection groove filled with Cu and so forth.

Next, a detailed explanation will be given of the cleaning apparatus104. FIGS. 2, 3, and 4 are a plan view, a front view, and a back view,respectively, schematically showing the cleaning apparatus 104. Thecleaning apparatus 104 includes a carrier station 4. The carrier station4 is arranged such that carriers each storing wafers W are sequentiallytransferred from other processing apparatuses onto the carrier station4. The carrier station 4 is also arranged such that carriers eachstoring wafers W processed in the cleaning apparatus 104 are transferredfrom the carrier station 4 to processing apparatuses for subsequentprocesses. The cleaning apparatus 104 further includes a process station2. The process station 2 includes a plurality of process units arrangedto respectively perform a cleaning process, a denaturing process, and arecovery process. A transfer station 3 is arranged to transfer a wafer Wbetween the process station 2 and carrier station 4. A chemical station5 is arranged to perform manufacture, preparation, and storage of achemical solution, purified water, gas, and so forth to be used in theprocess station 2.

Each carrier C contains therein wafers W essentially in a horizontalstate at regular intervals in the vertical direction (Z-direction). Thewafers W are transferred to and from the carrier C through one side ofthe carrier C, which is opened/closed by a lid 10 a (which is not shownin FIG. 2, but shown in FIGS. 3 and 4 in a detached state).

As shown in FIG. 2, the carrier station 4 has a table 6 on whichcarriers C can be placed at three positions arrayed in a Y-directiondefined in FIG. 2. Each carrier C is placed on the table 6 such that theside provided with the lid 10 a faces a partition wall 8 a between thecarrier station 4 and transfer station 3. The partition wall 8 a haswindow portions 9 a formed therein at positions corresponding to themount positions for carriers C. Each of the window portions 9 a isprovided with a shutter 10 on the transfer station 3 side to open/closethe window portion 9 a. This shutter 10 includes holding means (notshown) for holding the lid 10 a of a carrier C, so that the holdingmeans can hold the lid 10 a and withdraw it into the transfer station 3,as shown in FIGS. 3 and 4.

The transfer station 3 is provided with a wafer transfer unit 7 disposedtherein, which has a wafer transfer pick 7 a for holding a wafer W. Thewafer transfer unit 7 is movable in the Y-direction along guides 7 b(see FIGS. 3 and 4) extending on the floor of the transfer station 3 inthe Y-direction. The wafer transfer pick 7 a is slidable in anX-direction, movable up and down in the Z-direction, and rotatable inthe X-Y plane (θ rotation).

With the arrangement described above, the shutters 10 can be retreatedto allow the interior of the carriers C to communicate with the transferstation 3 through the window portions 9 a. In this state, the wafertransfer pick 7 a can access any one of the carriers C placed on thetable 6. Accordingly, the wafer transfer pick 7 a can transfer a wafer Wfrom any height position in each of the carriers C, and can transfer awafer W onto any height position in each of the carriers C.

The process station 2 includes two wafer mount units (TRS) 13 a and 13 bon the transfer station 3 side. For example, the wafer mount unit (TRS)13 b is used to place a wafer W when the wafer W is transferred from thetransfer station 3 to the process station 2. The wafer mount unit (TRS)13 a is used to place a wafer W when the wafer W is returned to thetransfer station 3 after it is subjected to a predetermined process inthe process station 2.

The process station 2 is provided with a fan and filter unit (FFU) 25arranged to send clean air into the process station 2 as a downflow.With this arrangement, a wafer W processed in the process station 2 isprevented from being contaminated where the processed wafer W is placedin the upper wafer mount unit (TRS) 13 a.

A partition wall 8 b is disposed between the transfer station 3 andprocess station 2, and has a window portion 9 b formed therein at aposition corresponding to the wafer mount units (TRS) 13 a and 13 b. Thewafer transfer pick 7 a can access the wafer mount units (TRS) 13 a and13 b through the window portion 9 b to transfer a wafer W between thecarriers C and wafer mount units (TRS) 13 a and 13 b.

On the rear side of the process station 2, there are denaturing units(VOS) 15 a to 15 f arranged to denature polymer residues etc. remainingafter an etching process or ashing process, by molecules of a gas (whichwill be referred to as “denaturing gas”, hereinafter) containing ozone(O₃) and water vapor. The term “denature” means that the properties ofpolymer residues etc. remaining on a wafer W are changed to be solublein purified water or a chemical solution. Further, the denaturing units(VOS) 15 a to 15 f can be used to denature a resist film by a denaturingprocess gas to be soluble in water, in place of ashing and removing ofthe resist film by an ashing process.

Each of the denaturing units (VOS) 15 a to 15 f includes a chamberdefining a disk-like space for accommodating a wafer W, which isairtight and can be dissembled into upper and lower portions (althoughthe structure thereof is not shown in detail). The chamber is providedwith a wafer mount stage disposed therein, which has proximity pinsdisposed on the surface to support a wafer W in a horizontal state and aheater built therein. The denaturing process gas is caused to flow in anessentially horizontal direction within the disk-like space inside thechamber.

Silylation units (SCH) 11 a and 11 b are disposed on the denaturingunits (VOS) 15 a and 15 d. Each of the silylation units is arranged toperform a silylation process to recover the damage of damaged portionsof an inter-level insulating film, which has been damaged or changed tohave a hydrophilic surface by an ashing process, cleaning process, orthe like.

FIG. 5 is a sectional view schematically showing the silylation unit(SCH) 11 a. The silylation unit (SCH) 11 a includes a chamber 41 foraccommodating a wafer W. The chamber 41 is formed of a stationary lowercontainer 41 a, and a lid 41 b that covers the lower container 41 a. Thelid 41 b is movable up and down by an elevating unit (not shown). Thelower container 41 a includes a hot plate 42, around which nitrogen gaswith vapor of a silylation agent carried therein, such as DMSDMA(Dimethylsilyldimethylamine), is supplied into the chamber 41.

In the structure shown in FIG. 5, liquid DMSDMA is vaporized by avaporizer 43, and is then carried by N₂ gas. Alternatively, vaporizedDMSDMA gas (i.e., DMSDMA vapor) may solely be supplied into the chamber41. As described later, when DMSDMA is supplied into the chamber 41, theinterior of the chamber 41 is maintained at a predetermined vacuumlevel. Accordingly, utilizing the pressure difference between thevaporizer 43 and chamber 41, DMSDMA gas is easily supplied into thechamber 41.

The hot plate 42 is adjustable in temperature within a range of, e.g.,50 to 200° C. The hot plate 42 is provided with pins 44 on the surfaceto support a wafer W. Where a wafer W is not mounted directly on the hotplate 42, the wafer W is prevented from being contaminated on its bottomsurface. The lower container 41 a is provided with a first seal ring 45disposed on the top face of the peripheral portion. The lid 41 b isprovided with a second seal ring 46 disposed on the bottom face of theperipheral portion. When the lid 41 b is pressed against the lowercontainer 41 a, the second seal ring 46 comes into contact with thefirst seal ring 45. The space defined between the first and second sealrings 45 and 46 can be pressure-reduced. When the pressure of this spaceis reduced, it is ensured that the chamber 41 is airtight. The lid 41 bhas an exhaust port 47 essentially at the center for exhausting nitrogengas with DMSDMA carried therein supplied into the chamber 41. Theexhaust port 47 is connected to a vacuum pump 49 through a pressureadjusting unit 48.

On the front side of the process station 2, there are cleaning units(CNU) 12 a to 12 d arranged to perform a chemical solution process orwater washing process on a wafer W treated by the denaturing units (VOS)15 a to 15 f, so as to remove denatured polymer residues etc.

Each of the cleaning units (CNU) 12 a to 12 d (although the structurethereof is not shown in detail) includes a rotatable spin chuck arrangedto hold a wafer W essentially in a horizontal state, and a cupsurrounding the spin chuck. A chemical solution nozzle is disposed tosupply a predetermined chemical solution onto the surface of a wafer Wheld by the spin chuck. A cleaning nozzle is disposed to mix nitrogengas into purified water and utilize the pressure of this nitrogen gas todeliver purified water mist onto the surface of a wafer W held by thespin chuck. A rinsing nozzle is disposed to supply purified water onto awafer W to perform a water washing process (rinsing process) thereon,after the wafer W is treated by the chemical solution process. Further,a gas spray nozzle is disposed to spray drying gas toward a wafer W,after the wafer W is treated by the water washing process.

Each of the cleaning units (CNU) 12 a to 12 d may be provided with anozzle arranged to supply onto a wafer W a chemical solution, such asdiluted hydrofluoric acid, for removing a silicon oxide film or siliconoxynitride film, and/or a nozzle arranged to supply onto a wafer W apeeling solution for performing a peeling process of a resist film usedas an etching mask.

The denaturing units (VOS) 15 a to 15 c and denaturing units (VOS) 15 dto 15 f described above have structures essentially symmetric withrespect to a partition wall 22 b. The silylation unit (SCH) 11 a andsilylation unit (SCH) 11 b have structures essentially symmetric withrespect to the partition wall 22 b. Similarly, the cleaning units (CNU)12 a and 12 b and cleaning units (CNU) 12 c and 12 d have structuresessentially symmetric with respect to the partition wall 22 a.

A main wafer transfer unit 14 is disposed essentially at the center ofthe process station 2, and is arranged to transfer a wafer W within theprocess station 2. The main wafer transfer unit 14 has a wafer transferarm 14 a for transferring a wafer W. The main wafer transfer unit 14 isrotatable about a Z-axis. Further, the wafer transfer arm 14 a ismovable back and forth in a horizontal direction, and movable up anddown in the Z-direction. With this arrangement, the main wafer transferunit 14 can access the respective units disposed in the process station2 to transfer a wafer W between the units, without moving itself in theX-direction.

The chemical station 5 includes a chemical solution storage portion 16that stores various chemical solutions to be used in various processingunits disposed in the process station 2. A liquid supply portion 17including a plurality of pumps and switching valves is disposed tosupply various chemical solutions stored in the chemical solutionstorage portion 16 to predetermined processing units. A purified watersupply portion 18 is disposed to supply purified water to the cleaningunits (CNU) 12 a to 12 d. A gas supply portion 19 is disposed to supplypredetermined gases to various processing units.

Next, an explanation will be given of the structure of the etchingapparatus 106. FIG. 6 is a plan view schematically showing the structureof the etching apparatus 106. The etching apparatus 106 includes etchingunits 51 and 52 for performing a plasma etching process, and silylationunits (SCH) 53 and 54. These units 51 to 54 are disposed to respectivelycorrespond to four sides of a hexagonal wafer transfer chamber 55. Theother two sides of the wafer transfer chamber 55 are respectivelyconnected to load-lock chambers 56 and 57. A wafer I/O chamber 58 isconnected to the load-lock chambers 56 and 57 on the side opposite tothe wafer transfer chamber 55. The wafer I/O chamber 58 has three ports59, 60, and 61 on the side opposite to the load-lock chambers 56 and 57,wherein the ports are used for respectively connecting three carriers Cthat can contain wafers W.

The etching units 51 and 52, silylation units (SCH) 53 and 54, andload-lock chambers 56 and 57 are connected to the sides of the wafertransfer chamber 55 respectively through gate valves G, as shown in FIG.6. Each of these units and chambers communicates with the wafer transferchamber 55 when the corresponding gate valve G is opened, and is blockedfrom the wafer transfer chamber 55 when the corresponding gate valve Gis closed. Gate valves G are also disposed between the load-lockchambers 56 and 57 and the wafer I/O chamber 58. Each of the load-lockchambers 56 and 57 communicates with the wafer I/O chamber 58 when thecorresponding gate valve G is opened, and is blocked from the wafer I/Ochamber 58 when the corresponding gate valve G is closed.

The wafer transfer chamber 55 is provided with a wafer transfer unit 62disposed therein, for transferring wafers W to and from the etchingunits 51 and 52, silylation units (SCH) 53 and 54, and load-lockchambers 56 and 57. The wafer transfer unit 62 is disposed essentiallyat the center of the wafer transfer chamber 55. The wafer transfer unit62 includes two rotation/stretch portions 63, which are rotatable andextensible/contractible. Two blades 64 a and 64 b, each for supporting awafer W, are respectively connected to the distal ends of therotation/stretch portions 63. The two blades 64 a and 64 b are connectedto the rotation/stretch portions 63 to face opposite directions. Theinterior of the wafer transfer chamber 55 can be maintained at apredetermined vacuum level.

The wafer I/O chamber 58 is provided with a HEPA filter (not shown)disposed on the ceiling. Clean air is supplied through the HEPA filterinto the wafer I/O chamber 58 in a downflow state. A wafer W istransferred to and from the wafer I/O chamber 58 within a clean airatmosphere at atmospheric pressure. Each of the three ports 59, 60, and61 of the wafer I/O chamber 58 for connecting a carrier C is providedwith a shutter (not shown). A carrier C, which contains wafers W or isempty, is directly connected to each of the ports 59, 60, and 61. Theshutter is then opened for the carrier C to communicate with the waferI/O chamber 58 while preventing inflow of outside air. An alignmentchamber 65 for performing alignment of a wafer W is disposed on one sideof the wafer I/O chamber 58.

The wafer I/O chamber 58 is provided with a wafer transfer unit 66disposed therein, for transferring wafers W to and from the carriers Cand load-lock chambers 56 and 57. The wafer transfer unit 66 includesarticulated arm structures respectively having hands 67 at the distalends. The wafer transfer unit 66 is movable on a rail 68 in a directionin which the carriers C are arrayed, to transfer a wafer W placed oneach of the hands 67. A control section 69 is arranged to control theoperation of the wafer transfer units 62 and 66 and the entire system.

The silylation units (SCH) 53 and 54 have almost the same structure asthat of the silylation units (SCH) 11 a and 11 b. Accordingly, thestructure of the silylation units (SCH) 53 and 54 is not shown indetail. However, the silylation units (SCH) 53 and 54 is arranged tofurther supply nitrogen gas containing water vapor at a predeterminedconcentration (or water vapor only) into the chamber 41.

When an inter-level insulating film, which has been damaged or changedto have a hydrophilic surface by an etching process or ashing process,is taken out into the atmosphere (air), moisture is adsorbed thereon andincreases the dielectric constant. Accordingly, after a wafer W issubjected to an etching process within the etching apparatus 106, thewafer W is subsequently subjected to a silylation process within theetching apparatus 106, without exposing the wafer W to the atmosphere(air). With this arrangement, the dielectric constant is prevented frombeing increased due to moisture adsorption.

In the etching apparatus 106, a wafer W treated by an etching process inthe etching units 51 and 52 is transferred to the silylation units (SCH)53 and 54 in a vacuum atmosphere. In this case, portions damaged byetching scarcely absorb moisture, and thus may suffer a difficulty incausing a silylation reaction.

In light of this, the silylation units (SCH) 53 and 54 are arranged tosupply water vapor into the chamber 41. This arrangement allows damagedportions to moderately cause a reaction for absorbing moisture, whichfacilitates the silylation reaction. As described previously, however,if the reaction for absorbing moisture is excessively caused, this mayadversely inhibit the silylation reaction. Accordingly, it is necessaryto control the supply of water vapor to prevent such reactioninhibition.

Next, an explanation will be given of a method for forming aninterconnection groove in an inter-level insulating film disposed on thewafer W, performed by the wafer processing system. FIG. 7 is a flowchartshowing a process for forming an interconnection structure by use of asingle damascene method. FIG. 8 comprises sectional views showingsequentially ordered steps of the process shown in FIG. 7.

At first, the following structure is prepared on a wafer W (the wafer Witself is not shown). Specifically, an insulating film 70 is disposed onthe wafer W, in which a lower interconnection line (copperinterconnection line) 72 is embedded with a barrier metal film 71interposed therebetween, and a stopper film 73, such as an SiN film orSiC film, is disposed on the insulating film 70. The wafer W thusprepared is transferred into the SOD apparatus 101, in which aninter-level insulating film 74, such as a Low-k film, is formed on thestopper film 73 (Step S1 and FIG. 8, (a)).

Then, the wafer W with the inter-level insulating film 74 formed thereonis transferred into the resist coating/development apparatus 102, inwhich an anti-reflective coating 75 a and a resist film 75 b aresequentially formed on the inter-level insulating film 74. Then, thewafer W is transferred into the light exposure apparatus 103, in whichthe wafer W is subjected to a light exposure process with apredetermined pattern. Then, the wafer W is transferred back into theresist coating/development apparatus 102, in which the resist film 75 bis subjected to a development process performed by the developing unitto form a predetermined circuit pattern on the resist film 75 b (Step S2and FIG. 8, (b)).

Then, the wafer W is transferred into the etching apparatus 106, inwhich an etching process is performed on the wafer W (Step S3).Consequently, a via-hole 78 a reaching the stopper film 73 is formed inthe inter-level insulating film 74 (FIG. 8, (c)). In FIG. 8, (c), areference symbol 79 a denotes a damaged portion, which will be explainedin detail. The wafer W thus treated by the etching process istransferred into the ashing apparatus 105, in which an ashing process isperformed to ash the anti-reflective coating 75 a and resist film 75 b(Step S4).

The wafer W thus treated by the ashing process is transferred into thecleaning apparatus 104, in which the wafer W is processed by one of thedenaturing units (VOS) 15 a to 15 f. In this process, polymer residuesetc. remaining on the wafer W treated by the etching process and ashingprocess are denatured to be soluble in water (Step S5). If thedenaturing units (VOS) 15 a to 15 f can be used to perform a process fordenaturing the anti-reflective coating 75 a and resist film 75 b, thisdenaturing process may be used in place of the ashing process. The waferW treated by the denaturing process is transferred into one of thecleaning units (CNU) 12 a to 12 d, in which a process is performed toremove the denatured polymer residues etc. (Step S6 and FIG. 8, (d)).

When the etching process, ashing process, and/or subsequent waterwashing process are performed as described above, the sidewall of thevia-hole 78 a formed in the inter-level insulating film 74 is damaged.Specifically, the damaged portions react with moisture, so the number ofmethyl groups is decreased and the number of hydroxyl groups isincreased near the sidewall of the via-hole 78 a, which increases thedielectric constant. If the via-hole 78 a with the damaged portions 79 aformed in the sidewall is filled with a metal material to form aninterconnection line, the parasitic capacitance between interconnectionlines is increased, so a signal delay occurs and the insulation betweeninterconnection lines is deteriorated. Although FIG. 8, (c) and (d),schematically shows the damaged portions 79 a, the boundary between adamaged portion 79 a and non-damaged portion is not clear, unlike in thedrawings.

Accordingly, in order to recover the damage of the damaged portions 79 aof the inter-level insulating film 74, the wafer W is transferred intoone of the silylation units (SCH) 11 a and 11 b, in which a silylationprocess is performed for the damaged portions (Step S7 and FIG. 8, (e)).The conditions of the silylation process are suitably selected inaccordance with the type of the silylation agent, as follows. Forexample, the temperature of the vaporizer 43 is set to be from a roomtemperature to 50° C. The silylation agent flow rate is set to be 0.1 to1.0 g/min. The N₂ gas (purge gas) flow rate is set to be 1 to 10 L/min.The process pressure is set to be 666 to 95,976 Pa (5 to 720 Torr). Thetemperature of the hot plate 42 is set to be from a room temperature to200° C. Where DMSDMA is used as the silylation agent, the followingmethod may be used, for example. Specifically, the hot plate 42 is setat 100° C., and the internal pressure of the chamber 41 is decreased to5 Torr (=666 Pa). Then, DMSDMA vapor carried by nitrogen gas is suppliedinto the chamber 41 until the internal pressure reaches 55 Torr. Then,the process is performed for, e.g., three minutes, while maintaining thepressure. The silylation reaction using DMSDMA is expressed by thefollowing reaction formula 1.

The wafer W thus treated by the silylation process is transferred intothe etching apparatus 106, in which an etching process is performed toremove the stopper film 73 (Step S8 and FIG. 8, (f)). Then, the wafer Wis transferred into the cleaning apparatus 104, in which a cleaningprocess is performed by one of the cleaning units (CNU) 12 a to 12 d(Step S9). When the etching process and/or cleaning process areperformed, the sidewall of the via-hole 78 a formed in the inter-levelinsulating film 74 is damaged, so damaged portions 79 b are formed.Accordingly, in order to recover the damage of the damaged portions 79b, the wafer W is transferred into one of the silylation units (SCH) 11a and 11 b, in which a silylation process is performed thereon (Step S10and FIG. 8, (g)).

Thereafter, the wafer W is transferred into the sputtering apparatus107, in which a barrier metal film and a Cu seed layer (i.e., platingseed layer) are formed on the inner surface of the via-hole 78 a (StepS11). Then, the wafer W is transferred into the electrolytic platingapparatus 108, in which a metal 76, such as copper, is embedded in thevia-hole 78 a by electrolytic plating (Step S12). Then, the wafer W issubjected to a heat process to perform an annealing process of the metal76 embedded in the via-hole 78 a (no annealing apparatus is shown inFIG. 1). Then, the wafer W is transferred into the CMP apparatus 109, inwhich a planarization process is performed on the wafer W by a CMPmethod (Step S13 and FIG. 8, (h)).

As described above, according to a method for forming an interconnectiongroove, the sidewall of the via-hole 78 a formed in the inter-levelinsulating film 74 is damaged by etching, ashing, and/or cleaning, but asilylation process is performed for damaged portions to recovery thedamage. Consequently, it is possible to provide a groove interconnectionwith excellent electrical characteristics, and to thereby improve thereliability of a semiconductor device.

In the explanation given above, a silylation process is performed afterthe process performed by the cleaning units (CNU) 12 a to 12 d isfinished. However, where the inter-level insulating film 74 is damagedor may be damaged by a predetermined process, this process may befollowed by a silylation process. For example, a silylation process ispreferably performed by the silylation units (SCH) 53 and 54 disposed inthe etching apparatus 106 immediately after the etching process of StepS3 or S8, in place of or in addition to the process performed by thecleaning units (CNU) 12 a to 12 d. Further, a silylation process ispreferably performed by the silylation units (SCH) 11 a and 11 bdisposed in the cleaning apparatus 104 immediately after the ashingprocess of Step S4.

FIG. 9A is a graph showing how the relationship between leakage currentand cumulative probability differs depending on the presence and absenceof a silylation process. FIG. 9B is a graph showing how the relationshipbetween voltage and leakage current differs depending on the presenceand absence of a silylation process. In other words, these graphs show adifference between the presence and absence of a silylation processafter the process of the cleaning units (CNU) 12 a to 12 d. The testsample that rendered the results shown in FIGS. 9A and 9B had the samestructure as that shown in FIG. 8, (h), wherein the inter-levelinsulating film 74 was formed of a low-k film selected from LKD (tradename) series of JSR Co. Ltd. As shown in FIGS. 9A and 9B, where thesilylation process was performed, the leakage current was decreased andthe breakdown voltage was improved, i.e., the insulation property of theinter-level insulating film was improved, as compared to the exampleperformed without the silylation process. Further, the dielectricconstant of the inter-level insulating film thus processed wasadditionally measured. As a result, it was confirmed that the exampleperformed with the silylation process rendered an improvement of 10 to20%, as compared to the example performed without the silylationprocess.

FIG. 10 is a flowchart showing a process for forming an interconnectionstructure by use of a dual damascene method. FIG. 11 comprises sectionalviews showing sequentially ordered steps of the process shown in FIG.10. For this process, the apparatuses used in the respective steps willnot be explained, because they have been clarified by the precedingexplanation.

At first, the following structure is prepared on a wafer W (the wafer Witself is not shown). Specifically, an insulating film 70 is disposed onthe wafer W, in which a lower interconnection line (copperinterconnection line) 72 is embedded with a barrier metal film 71interposed therebetween, and a stopper film 73, such as an SiN film orSiC film, is disposed on the insulating film 70. The wafer W thusprepared is then provided with an inter-level insulating film 74, suchas a Low-k film, formed on the stopper film 73 (Step S101 and FIG. 11,(a)).

Then, an anti-reflective coating 75 a and a resist film 75 b aresequentially formed on the inter-level insulating film 74. Then, theresist film 75 b is subjected to a light exposure process with apredetermined pattern, and then to a development process to form anetching pattern on the resist film 75 b (Step S102 and FIG. 11, (b)).Then, an etching process using the resist film 75 b as an etching maskis performed to form a via-hole 78 a reaching the stopper film 73 (StepS103 and FIG. 11, (c)). In FIG. 11, (c), a reference symbol 79 a denotesa damaged portion generated by the etching process. Then, an ashingprocess is performed to remove the resist film 75 b and anti-reflectivecoating 75 a (Step S104). Then, a cleaning process is performed toremove polymer residues etc. generated by the preceding etching processand/or ashing process (Step S105). Further, a silylation process isperformed to recover the damage of the damaged portion 79 a of theinter-level insulating film 74 (Step S106 and FIG. 11, (d)). Asilylation process may be performed after the etching of Step S103and/or the ashing of Step S104.

Then, a protection film 81 is formed on the surface of the inter-levelinsulating film 74 (Step S107). Then, an anti-reflective coating 82 aand a resist film 82 b are sequentially formed on the protection film81. Then, the resist film 82 b is subjected to a light exposure processwith a predetermined pattern, and then to a development process to forma circuit pattern on the resist film 82 b (Step S108 and FIG. 11, (e)).The protection film 81 can be formed from a predetermined chemicalsolution applied by spin coating in the SOD apparatus 101. Theprotection film 81 is not necessarily required, so the anti-reflectivecoating 82 a and resist film 82 b may be formed directly on theinter-level insulating film 74.

Then, an etching process using the resist film 82 b as an etching maskis performed to form a trench 78 b in the inter-level insulating film 74(Step S109 and FIG. 11, (f)). Then, an ashing process is performed toremove the resist film 82 b and anti-reflective coating 82 a (StepS110). The process of Step S110 may be performed by the denaturing units(VOS) 15 a to 15 f. In FIG. 11, (f), a reference symbol 79 b denotes adamaged portion generated by the etching process of Step S109.

Then, a cleaning process is performed to remove polymer residues etc.generated by the preceding etching process and/or ashing process and theprotection film 81 (Step S111). Further, a silylation process isperformed to recover the damage of the damaged portion 79 b of theinter-level insulating film 74 (Step S112 and FIG. 11, (g)). Also inthis case, a silylation process may be performed after the etching ofStep S109 and/or the ashing of Step S110.

Then, an etching process for removing the stopper film 73 and a processfor removing residues are performed (Step S113). Thereafter, asilylation process is performed to recover the damage of damagedportions generated by the etching process or the like in the via-hole 78a and trench 78 b (Step S114 and FIG. 11, (h)). FIG. 11, (h), shows astate after this silylation process.

Thereafter, a barrier metal film and a Cu seed layer are formed on theinner surface of the via-hole 78 a and trench 78 b. Then, a metal 76,such as copper, is embedded in the via-hole 78 a and trench 78 b to forma plug by electrolytic plating. Then, the wafer W is subjected to a heatprocess to perform an annealing process of the metal 76 embedded in thevia-hole 78 a and trench 78 b. Then, a planarization process isperformed on the wafer W by a CMP method (Step S115 and FIG. 11, (i)).

FIG. 12 is a flowchart showing another process for forming aninterconnection structure by use of a dual damascene method. FIG. 13comprises sectional views showing sequentially ordered steps of theprocess shown in FIG. 12. Also for this process, the apparatuses used inthe respective steps will not be explained, because they have beenclarified by the preceding explanation.

At first, the following structure is prepared on a wafer W (the wafer Witself is not shown). Specifically, an insulating film 70 is disposed onthe wafer W, in which a lower interconnection line (copperinterconnection line) 72 is embedded with a barrier metal film 71interposed therebetween, and a stopper film 73, such as an SiN film orSiC film, is disposed on the insulating film 70. The wafer W thusprepared is then provided with an inter-level insulating film 74, suchas a Low-k film, a hard mask layer 86, an anti-reflective coating 87 a,and a resist film 87 b sequentially formed on the stopper film 73. Then,the resist film 87 b is subjected to a light exposure process with apredetermined pattern, and then to a development process to form anetching pattern on the resist film 87 b (Step S201 and FIG. 13, (a)).

Then, an etching process using the resist film 87 b as an etching maskis performed to pattern the hard mask layer 86 (Step S202). Then, theresist film 87 b and anti-reflective coating 87 a are removed (Step S203and FIG. 13, (b)). Then, an anti-reflective coating 88 a and a resistfilm 88 b are sequentially formed on the hard mask layer 86. Then, theresist film 88 b is subjected to a light exposure process with apredetermined pattern, and then to a development process to form anetching pattern on the resist film 88 b (Step S204 and FIG. 13, (c)).

Then, an etching process using the resist film 88 b as an etching maskis performed to form a via-hole 78 a reaching the stopper film 73 (StepS205 and FIG. 13, (d)). Then, an ashing process is performed to removethe resist film 88 b and anti-reflective coating 88 a, and a process forremoving polymer residues etc. is performed (Step S206 and FIG. 13,(e)). If damaged portions are generated in the inter-level insulatingfilm 74 by the etching process of Step S205, a silylation process may beperformed before the ashing process. Further, if damaged portions aregenerated in the inter-level insulating film 74 by the ashing processand residue removing process of Step S206, a silylation process may beperformed after this step.

After Step S206 is finished, the hard mask layer 86 with a predeterminedpattern formed therein is exposed. Then, an etching process using thehard mask layer 86 as an etching mask is performed to form a trench 78 b(Step S207). At this time, where damaged portions have been generated inthe inter-level insulating film 74, a silylation process may beperformed immediately thereafter. Then, an ashing process or chemicalsolution process is performed to remove the hard mask layer 86 (StepS208 and FIG. 13, (f)). For example, a silylation process is performedafter the removing process of the hard mask layer 86 (Step S209), torecover the damage of damaged portions generated in the inter-levelinsulating film 74 before Step S208. FIG. 13, (f), shows a state afterthe damage recovery.

Then, an etching process for removing the stopper film 73 and a processfor removing residues are performed (Step S210 and FIG. 13, (g)). Then,a silylation process is performed again to recover the damage of damagedportions (not shown) generated by the etching process or the like in thevia-hole 78 a and trench 78 b (Step S211). Thereafter, a barrier metalfilm and a Cu seed layer are formed on the inner surface of the via-hole78 a and trench 78 b. Then, a metal 76, such as copper, is embedded inthe via-hole 78 a and trench 78 b to form a plug by electrolyticplating. Then, the wafer W is subjected to a heat process to perform anannealing process of the metal 76 embedded in the via-hole 78 a andtrench 78 b. Then, a planarization process is performed on the wafer Wby a CMP method (Step S212 and FIG. 13, (h)).

Table 1 shows results of an experiment in relation to a change ink-value where a silylation process was performed by the silylation units(SCH) 11 a and 11 b of the cleaning apparatus 104. In this experiment, aporous MSQ (Porous methyl-hydrogen-SilsesQuioxane) film is used as a lowdielectric constant insulating film (low-k film). An etching processusing an etching gas of C₄F₈/Ar/N₂ was performed by the etching units 51and 52 of the etching apparatus 106. An ashing process using an ashinggas consisting solely of O₂ gas was performed by the ashing apparatus105. Further, HMDS (Hexamethyldisilazane) was used as a silylationagent. The porous MSQ film is an insulating film (SOD film) formed byspin coating, which is a siloxane film having Si—O—Si bonds. Thesilylation process was performed at 2.5 Torr and 200° C. for 15 minutes.

TABLE 1 Process state of test sample k-value Before etching process 2.36(after film formation) After etching 2.80 process/ashing process Aftersilylation process 2.63

As shown in Table 1, the k-value was 2.36 before the etching, and it wasincreased to 2.80 after the etching process and ashing process. However,the k-value was decreased to 2.63 after the silylation process.

The silylation agent is not limited to a specific one, and this agentmay comprise any substance as long as it causes a silylation reaction.However, it is preferable to use a substance having a relatively smallmolecular structure selected from the compounds including silazane bonds(Si—N bonds) in molecules, such as a substance having a molecular weightpreferably of 260 or less, and more preferably of 170 or less. Namely,examples other than DMSDMA and HMDS are TMSDMA(Dimethylaminotrimethylsilane), TMDS (1,1,3,3-Tetramethyldisilazane),TMSPyrole (1-Trimethylsilylpyrole), BSTFA(N,O-Bis(trimethylsilyl)trifluoroacetamide), and BDMADMS(Bis(dimethylamino)dimethylsilane). The chemical structures of thesesubstances are as follows.

Of the compounds set out above, TMSDMA and TMDS are preferably usedbecause they are high in the effect of recovering the dielectricconstant, and the effect of decreasing the leakage current. Further, inlight of the stability after silylation, it is preferable to use asubstance (such as TMSDMA or HMDS) having a structure in which the Si ofeach silazane bond is bonded to three alkyl groups (such as methylgroups).

In the wafer processing system, the ashing apparatus 105 and etchingapparatus 106 are separately formed. However, the etching units 51 and52 of the etching apparatus 106 may be used to perform an ashingprocess, while using a different process gas. Further, if they aremodified to supply a silylation agent, such as DMSDMA, they can performa silylation process.

FIG. 14 is a sectional view schematically showing the structure of anetching unit 90 which can perform an etching process, an ashing process,and a silylation process. This etching unit 90 may be disposed in theetching apparatus 106, in place of the etching units 51 and 52 andsilylation units (SCH) 53 and 54 thereof shown in FIG. 6.

The etching unit 90 includes an essentially cylindrical plasma processchamber (plasma process container) 302. The plasma process chamber 302is made of, e.g., aluminum with an anodization-processed(alumite-processed) surface and set at the ground potential.

The plasma process chamber 302 contains a susceptor pedestal 304disposed therein on the bottom through an insulating plate 303, such asa ceramic. A susceptor 305 is disposed on the susceptor pedestal 304.The susceptor 305 is used as a lower electrode and has a top face, onwhich a wafer W is placed. A high-pass filter (HPF) 306 is connected tothe susceptor 305.

The susceptor pedestal 304 is provided with a temperature adjustingmedium space 307 formed therein. The temperature adjusting medium space307 is connected to a supply line 308 and an exhaust line 309. Atemperature adjusting medium is supplied through the supply line 308into the temperature adjusting medium space 307. The temperatureadjusting medium is circulated in the temperature adjusting medium space307 and is exhausted from the exhaust line 309. Consequently, thesusceptor 305 is adjusted to a predetermined temperature.

The susceptor 305 is formed of a circular plate having a projection atthe center of the top, on which an electrostatic chuck 310 is disposed.The electrostatic chuck 310 has a structure in which an electrode 312 issandwiched between insulating layers 311, and is connected to a DC(direct current) power supply 313. When a DC voltage of, e.g., about 1.5kV is applied from the DC power supply 313 to the electrode 312, thewafer W is attracted and held on the electrostatic chuck 310 by anelectrostatic force.

Further, a gas passage 314 is formed in the insulating plate 303,susceptor pedestal 304, susceptor 305, and electrostatic chuck 310 tosupply a heat transmission medium (such as He gas) to the bottom of thewafer W. When the heat transmission medium is supplied through the gaspassage 314, the temperature of the wafer W is adjusted to apredetermined value by heat transmitted through the heat transmissionmedium between the susceptor 305 and wafer W.

Where the wafer W is set at a high temperature in an ashing process orsilylation process, the heat transmission medium is set for the hightemperature. In the etching unit 90, however, when an etching process,ashing process, and/or silylation process are actually performed, ittakes time to stabilize the temperature of the wafer W in changing theset temperatures for respective processes. For this purpose, a coolingelement is preferably built in the susceptor 305 to control thetemperature.

An annular focus ring 315 is disposed on the top of the susceptor 305 atthe rim to surround the wafer W placed on the electrostatic chuck 310.The focus ring 315 is made of an insulative material, such as a ceramicor quartz, or a conductive material.

An upper electrode 321 is disposed above the susceptor 305 to face thesusceptor 305 in parallel therewith. The upper electrode 321 issupported inside the plasma process chamber 302 through an insulatingbody 322. The upper electrode 321 includes an electrode plate 324, whichdefines a counter face opposite to the susceptor 305 and has a number ofgas delivery holes 323, and an electrode support 325 supporting theelectrode plate 324. The electrode plate 324 is made of an insulativematerial or dielectric material. In this embodiment, the electrode plate324 is made of silicon. The electrode support 325 is made of aconductive material, such as aluminum with an anodization-processed(alumite-processed) surface. The distance between the susceptor 305 andupper electrode 321 is adjustable.

The electrode support 325 has a gas feed port 326 formed therein at thecenter, which is connected to a gas supply line 327. The gas supply line327 is connected to a process gas supply source 330 through a valve 328and a mass-flow controller 329.

A predetermined process gas for a plasma process is supplied from theprocess gas supply source 330. FIG. 14 shows only one process gas supplysystem comprising the gas supply line 327, valve 328, mass-flowcontroller 329, and process gas supply source 330, but a plurality ofprocess gas supply systems are provided in practice. These process gassupply systems are arranged to supply gases, such as O₂ gas, NH₃ gas,CO₂ gas, Ar gas, N₂ gas, CF₄ gas, C₄F₈ gas, water vapor, and silylationagent, e.g., DMSDMA, into the plasma process chamber 302 atindependently controlled flow rates.

The bottom of the plasma process chamber 302 is connected to an exhaustunit 335 through an exhaust line 331. The exhaust unit 335 includes avacuum pump, such as a turbo molecular pump, to set the interior of theplasma process chamber 302 at a predetermined vacuum atmosphere (such as0.57 Pa) or less.

The plasma process chamber 302 has a gate valve 332 on the sidewall.When the wafer W is loaded and unloaded to and from the plasma processchamber 302, the gate valve 332 is opened.

The upper electrode 321 is connected to a first RF (radio frequency)power supply 340 through a feed line provided with a first matching unit341. The upper electrode 321 is further connected to a low-pass filter(LPF) 342. The first RF power supply 340 is arranged to supply an RFpower with a high frequency of, e.g., 50 to 150 MHz for plasmageneration. Where an RF power with such a high frequency is applied tothe upper electrode 321, plasma can be generated with a high density anda preferable dissociation state within the plasma process chamber 302,so the plasma process can be performed under a low pressure condition.The frequency of the first RF power supply 340 is preferably set to be50 to 150 MHz, and typically at or near 60 MHz, as shown in FIG. 14.

On the other hand, the lower electrode or susceptor 305 is connected toa second RF power supply 350 through a feed line provided with a secondmatching unit 351. The second RF power supply 350 is used for generatinga self bias voltage and is arranged to supply a power with a frequencyof, e.g., several hundred Hz to ten and several MHz, which is lower thanthat of the first RF power supply 340. Where a power with such a highfrequency is applied to the susceptor 305, a suitable ion action can beapplied to the wafer W without damaging it. The frequency of the secondRF power supply 350 is typically set at, e.g., 2 MHz, as shown in FIG.14, or alternatively at 3.2 MHz or 13.56 MHz.

Next, an explanation will be given of steps of a process performed on awafer W in the etching unit 90 described above. FIG. 15 comprisessectional views showing the surface structure of a wafer obtained insteps of a process using the etching unit shown in FIG. 14. As shown inFIG. 15, (a), on a wafer W (not shown), an organic low dielectricconstant film (such as Porous MSQ) 601, an SiCN film 602, ananti-reflective coating (BARC) 603, and a resist film 604 are disposedin this order from below. The resist film 604 is already patterned.

At first, the gate valve 332 is opened, and a wafer W is transferredinto the plasma process chamber 302 and is placed on the susceptor 305by the blade 64 a (or 64 b) of the wafer transfer unit 62. Then, a DCvoltage of, e.g., about 1.5 kV is applied from the DC power supply 313to the electrode 312 of the electrostatic chuck 310, so that the wafer Wis attracted and held on the electrostatic chuck 310 by an electrostaticforce. Then, the blade 64 a of the wafer transfer unit 62 is retreatedfrom the plasma process chamber 302.

After the gate valve 332 is closed, the interior of the plasma processchamber 302 is exhausted and set at a predetermined vacuum level (suchas 4 Pa or less) by the exhaust unit 335. Further, a predeterminedprocess gas (such as CF₄ gas solely) is supplied at a predetermined flowrate from the process gas supply source 330 through the mass-flowcontroller 329 into the plasma process chamber 302. Furthermore, an RFpower set at a predetermined level with a high frequency (such as 60MHz) for plasma generation is applied from the first RF power supply 340to the upper electrode 321. Under these conditions, plasma of theprocess gas is generated. At this time, an RF power set at apredetermined level with a low frequency (such as 2 MHz) for self biasvoltage generation is applied from the second RF power supply 350 to thelower electrode or susceptor 305. With this RF power, ions in plasma areattracted onto the wafer W to subject the anti-reflective coating 603 toan etching process using the resist film 604 as an etching mask.

Then, the SiCN film 602 and organic low dielectric constant film 601 aresequentially subjected to etching processes using the same procedures ofthe etching process for the anti-reflective coating 603, but usingdifferent process gases, so that the structure shown in FIG. 15, (b), isobtained. For example, the SiCN film 602 is etched by plasma of amixture gas of C₄F₈/Ar/N₂. The organic low dielectric constant film 601is etched by plasma of a mixture gas of CF₄/Ar. Then, using the sameprocedures of the etching process, but using a process gas, such as O₂gas, NH₃ gas, or CO₂ gas, an ashing process is performed by plasma ofthe process gas to remove the resist film 604 and anti-reflectivecoating 603. Consequently, the structure shown in FIG. 15, (d), isobtained. In FIG. 15, (c), damaged portions generated by the etchingprocess and/or ashing process are schematically indicated by a referencesymbol 605.

As described above, where the etching process and ashing process aresequentially performed, it is preferable to perform so-called two-stepashing. Specifically, in the firs step, cleaning for the interior ofplasma process chamber 302 is performed without a bias voltage appliedfrom the second RF power supply 350. Then, in the second step, an ashingprocess is performed on the wafer W with a bias voltage applied from thesecond RF power supply 350.

Then, while the pressure inside the plasma process chamber 302 is set ata predetermined vacuum level, a predetermined amount of water vapor issupplied through the delivery holes 323 formed in the upper electrode321 into the plasma process chamber 302. Consequently, a suitable amountof moisture is adsorbed on the damaged portions generated by the etchingprocess and ashing process in the organic low dielectric constant film601.

Then, the interior of the plasma process chamber 302 is exhausted, andthen stops being exhausted when the interior of the plasma processchamber 302 reaches a predetermined vacuum level. Then, while theinterior of the plasma process chamber 302 is maintained at thepredetermined vacuum level, the wafer W is heated to a temperature of,e.g., 50 to 200° C. that can cause a silylation reaction to start.Thereafter, a predetermined amount of silylation agent gas, such asDMSDMA gas, is supplied through the delivery holes 323 formed in theupper electrode 321 into the plasma process chamber 302. The silylationagent gas is supplied to increase the pressure inside the plasma processchamber 302, which is then maintained for a predetermined time.Consequently, as shown in FIG. 15, (d), the silylation recovers thedamage of the damaged portions 605 of the organic low dielectricconstant film 601. After the silylation process, even if the wafer Wthus treated is exposed to the atmosphere (air), the organic lowdielectric constant film 601 scarcely absorbs moisture, therebymaintaining the property.

In FIG. 15, (d), in order to schematically show the recovery of thedamaged portions 605, the structure of the organic low dielectricconstant film 601 is shown such that the damaged portions 605 have beenreturned to the original state. However, after the damaged portions 605are recovered, the chemical structure is not necessarily the same as thechemical structure of the organic low dielectric constant film 601.

The recovery of damage by the silylation process in the organic lowdielectric constant film 601 can be quantitatively assessed byperforming a hydrofluoric acid immersing process on the wafer W. This isso because, for example, the sidewall of the groove pattern of theorganic low dielectric constant film 601 is changed to SiO₂ by theashing process using oxygen plasma. If the damage is not recovered, SiO₂is dissolved by hydrofluoric acid, and the organic low dielectricconstant film 601 suffers side etching.

FIG. 16A comprises sectional views showing a change in the shape of agroove caused by a hydrofluoric acid immersing process where the groovehas not been treated by the silylation process. FIG. 16B comprisessectional views showing a change in the shape of a groove caused by ahydrofluoric acid immersing process where the groove has been treated bythe silylation process. In other words, these drawings show a differencebetween the presence and absence of the silylation process performed onthe state shown in FIG. 15, (c), to obtain the state shown in FIG. 15,(d), before the hydrofluoric acid (hydrofluoric acid aqueous solution)immersing process. As shown in FIG. 16A, where the silylation process isnot performed before the hydrofluoric acid process, SiO₂ generated bythe ashing process is dissolved by the hydrofluoric acid. In this case,the organic low dielectric constant film 601 suffers side etching andthe line width is thereby decreased. On the other hand, as shown in FIG.16B, where the silylation process is performed, no SiO₂ is exposed onthe sidewall of the groove pattern, and the corrosion resistancerelative to hydrofluoric acid is improved. In this case, the organic lowdielectric constant film 601 is prevented from suffering side etchingdue to the hydrofluoric acid.

Next, an explanation will be given of results of tests conducted toconfirm effects of the present invention.

(1) Measurement of dielectric constant, leakage current density, andwater content:

FIG. 17A is a side view showing a step of processing a test sample formeasuring dielectric constant, leakage current density, and moisturedesorption amount. FIG. 17B is a side view showing a test sample formeasuring dielectric constant, leakage current density, and moisturedesorption amount. Specifically, a test sample was prepared by forming aporous MSQ film as an SOD film on an Si substrate. Then, an etchingprocess and an ashing process were sequentially performed on the testsample to damage the porous MSQ film. Then, a silylation process using asilylation agent shown in Table 2 was performed, and then the dielectricconstant and leakage current density of the film were measured. Further,without performing the silylation process, the dielectric constant andleakage current density of the film were measured.

Both of the etching process and ashing process were performed in theetching unit 90 shown in FIG. 14. In these processes, the etching gaswas CF₄ and the ashing gas was O₂, NH₃, or CO₂. The silylation processwas performed in a unit having the same structure as the silylation unit(SCH) 11 a shown in FIG. 5. The silylation conditions were setdifferently in accordance with the type of silylation agent. For DMSDMA,the process temperature was set at 100° C. and the process time was setat 180 seconds. For TMSDMA, the process temperature was set at 150° C.and the process time was set at 150 seconds. For TMDS, the processtemperature was set at 180° C. and the process time was set at 900seconds. For BSTFA, BDMADMS, and TMSpytole, the process temperature wasset at 180° C. and the process time was set at 300 seconds. The flowrate of N₂ gas (purge gas) was set at 5.0 L/min. The temperature of thevaporizer 43 was set at a suitable value within a range of a roomtemperature to 50° C. in accordance of the type of silylation agent. Theflow rate of a silylation agent was set at a suitable value within arange of 0.1 to 1.0 g/mln in accordance of the type of silylation agent.The process pressure was set at a suitable value within a range of 666to 9,5976 Pa (5 to 720 Torr) in accordance of the type of silylationagent.

In order to measure the dielectric constant and leakage current density,as shown in FIG. 17B, an Al pad was mounted on the porous MSQ film ofthe test sample, and the k-value and leakage current were measured whileapplying a voltage between the Si substrate and Al pad. Table 2 alsoshows results of this test. The leakage current density is expressed bya measurement value at 1 MV/cm, as a representative value.

TABLE 2 Dielectric constant Leakage Ashing Silylation Recovery ratecurrent density gas agent k-value after ashing (%) (A/cm²) @1 MV/cmBefore process 2.47 —  3.28 × 10⁻¹⁰ Etching process only 3.25 — 1.13 ×10⁻⁵ O₂ No silylation 4.12 — 6.15 × 10⁻⁵ DMSDMA 3.16 58.1 5.47 × 10⁻⁶TMSDMA 2.94 71.6 5.52 × 10⁻⁷ TMDS 2.89 74.8 1.80 × 10⁻⁶ BSTFA 3.14 59.68.90 × 10⁻⁷ BDMADMS 3.80 19.0 1.49 × 10⁻⁵ TMSpyrole 3.59 31.7 3.28 ×10⁻⁵ NH₃ No silylation 3.88 — 6.50 × 10⁻⁵ DMSDMA 3.43 31.8 1.40 × 10⁻⁵TMSDMA 3.16 50.8 2.04 × 10⁻⁶ TMDS 3.22 47.0 1.04 × 10⁻⁶ BSTFA 3.61 19.15.29 × 10⁻⁵ BDMADMS 4.48 −43.1 1.69 × 10⁻⁴ TMSpyrole 3.63 17.5 3.10 ×10⁻⁵ CO₂ No silylation 4.25 — 3.62 × 10⁻⁵ DMSDMA 3.39 48.2 1.19 × 10⁻⁵TMSDMA 3.07 66.6 1.13 × 10⁻⁶ TMDS 3.22 57.6 5.31 × 10⁻⁶ BSTFA 3.42 46.62.92 × 10⁻⁶ BDMADMS 4.13 6.7 1.26 × 10⁻⁵ TMSpyrole 3.49 42.8 4.17 × 10⁻⁵

As shown in Table 2, an increase in the k-value and an increase in theleakage current density were suppressed in a case where the silylationprocess was performed after the ashing process, as compared to a casewhere the silylation process was not performed. Particularly, TMSDMA andTMDS were good in the effect of recovering the k-value and the effect ofdecreasing the leakage current density. As regards the relationshiprelative to the type of an ashing gas, the silylation process was mosteffective for a case where O₂ gas was used for the ashing process.

Further, a silylation process using one of various silylation agents wasperformed on a sample having the same structure shown in FIG. 17A. Then,the sample was heated at a heating-up rate of 1° C./second, and themoisture desorption amount thereof during this heating (i.e., the watercontent in the film) was measured by means of mass spectrometry. Thewater content in the film may deteriorate the dielectric constant and/orleakage current of the film. FIG. 18 is a graph showing how the moisturedesorption amount changes depending on the presence and absence of thesilylation process and the type of silylation agent. In FIG. 18, thevertical axis denotes a vale obtained where the moisture desorptionamount (desorption gas amount) from 100 to 500° C. was subjected tointegration by a unit of temperature and then normalized by the mass ofthe sample.

As shown in FIG. 18, the effect of decreasing the water content was goodfor O₂ ashing, without reference to the type of chemical solution. Onthe other hand, the effect of decreasing the water content was good forNH₃ ashing and CO₂ ashing, where TMSDMA or TMDS was used for thesilylation process.

(2) Test of corrosion resistance relative to diluted hydrofluoric acidprocess:

FIG. 19A is a view showing a test sample before a corrosion resistancetest using immersion in diluted hydrofluoric acid. FIG. 19B is a viewshowing the test sample after the corrosion resistance test usingimmersion in diluted hydrofluoric acid. Specifically, a test sample wasprepared by forming a porous MSQ film as an SOD film on an Si substrate.Then, a mask film was formed thereon and subjected to light exposure anddevelopment to form a trench pattern by a photolithography technique.Then, an etching process using the mask pattern as an etching mask isperformed on the porous MSQ film. Then, an ashing process using O₂, NH₃,or CO₂ as an ashing gas was performed to process residues of the etchingmask. Then, a trench structure having a pattern shown in FIG. 19A wasformed in the porous MSQ film.

Then, the test sample with this trench structure formed thereon wassubjected to a silylation process using each of the silylation agentsdescribed above. Then, the test sample was subjected to an immersingprocess using 0.5%-diluted hydrofluoric acid for 30 seconds. Then, asshown in FIG. 19B, the trench width was measured on the upper and lowersides of the trench (which will be referred to as “top CD” and “bottomCD”). Table 3 shows a result of comparison between the present andabsence of the silylation process before the diluted hydrofluoric acidprocess, in terms of an increased length in the top CD and an increasedlength in the bottom CD. The etching, ashing, and silylation processeswere performed under the same conditions used in the test (1).

TABLE 3 Increase in top CD/bottom CD Top CD/bottom (nm) after dilutedAshing CD (nm) after Silylation hydrofluoric acid gas ashing agentprocess O₂ 220/197 No silylation 67/53 DMSDMA 6/7 TMSDMA 4/3 TMDS 23/13BSTFA 7/4 BDMADMS 4/0 TMSpyrole 3/3 NH₃ 217/197 No silylation 73/53DMSDMA 70/44 TMSDMA 80/50 TMDS 77/37 BSTFA 76/60 BDMADMS 23/0  TMSpyrole27/27 CO₂ 223/197 No silylation 57/60 DMSDMA 7/3 TMSDMA 0/3 TMDS 17/17BSTFA 13/17 BDMADMS 4/3 TMSpyrole 30/17

As shown in Table 3, an increase in CD was essentially suppressed anddamage recovery was thus provided in a case where the silylation processwas performed before the diluted hydrofluoric acid process, as comparedto a case where the silylation process was not performed. Particularly,an increase in CD was remarkably suppressed where the silylation processwas performed after O₂ ashing. Of the silylation agents, TMSDMA rendereda good damage recovery effect for both of O₂ ashing gas and CO₂ ashinggas.

The present invention has been explained with reference to theembodiments described above, but the present invention is not limited tothe embodiments. For example, a film that can be subjected to asilylation process for damage recovery is not limited to the porous MSQfilm described above. Alternatively, for example, an SiOC-based film,which is an inorganic insulating film formed by CVD, may be used. Thisfilm can be prepared from a conventional SiO₂ film by introducing methylgroups (—CH₃) into Si—O bonds present on the film to mix S₁—CH₃ bondstherewith. Black Diamond (Applied Materials Ltd.), Coral (NovellusLtd.), and Aurora (ASM Ltd.) correspond to this type. An SiOC-based filmof the porous type (with a lot of pores) may be used. An MSQ-basedinsulating film of a dense type, as well as a porous type, may be used.

Further, a process may be performed, as follows. Specifically, avia-hole and/or a trench are formed, and then a barrier metal film and aCu seed layer are sequentially formed in the via-hole and/or trench.Then, copper is embedded in the via-hole and/or trench by electrolyticplating. Then, an annealing process and a CMP process are performed toform a copper interconnection line. Then, an ammonia plasma process isperformed to subject the copper interconnection line surface to ade-oxidation process. Then, a stopper film is formed thereon. In thiscase, a silylation process may be performed to recovery the damage ofdamaged portions generated by the ammonia plasma process.

INDUSTRIAL APPLICABILITY

According to the present invention, in the process for forming aninterconnection groove and/or a connection hole, the damage of damagedportions generated in an etching target film is recovered. Consequently,it is possible to improve electrical characteristics of the etchingtarget, and to thereby manufacture a reliable semiconductor device.

1. A semiconductor device manufacturing apparatus comprising: an etchingprocess section configured to perform an etching process using anetching gas on an etching target film disposed on a substrate, whileusing an etching mask having a circuit pattern and disposed on theetching target film, to form a groove or a hole in the etching targetfilm; an ashing process section configured to perform an ashing processusing an ashing gas on the etching mask to remove the etching mask fromthe etching target film, after the etching process; a silylation processsection configured to perform a silylation process using a silylationagent gas on an inner surface of the groove or the hole of the etchingtarget film to recover damages of the inner surface of the groove orhole inside a silylation chamber, the silylation process section beingarranged to supply water vapor into the silylation chamber to have theinner surface of the groove or hole having the damages cause a reactionfor absorbing moisture, which facilitates a silylation reaction; and acontrol section configured to control an operation of the apparatus,wherein the control section includes a non-transitory storage mediumthat stores a program for execution on a computer to control theapparatus, which, when executed, controls the apparatus to conduct asequence that performs the etching process on the etching target film,the ashing process on the etching mask, and the reaction for absorbingmoisture and the silylation process on the inner surface of the grooveor hole of the etching target film, in this order.
 2. The apparatusaccording to claim 1, wherein the silylation process section comprises:a vacuum chamber configured to maintain a vacuum state therein andserving as the silylation chamber: a vacuum-exhaust system connected tothe vacuum chamber and provided with a pressure adjusting mechanism; agas supply system connected to the vacuum chamber and configured tosupply the silylation agent gas into the vacuum chamber; and a hot platedisposed inside the vacuum chamber and configured to control temperatureof the substrate placed thereon.
 3. The apparatus according to claim 1,wherein the ashing process section comprises a process gas supply systemconfigured to supply, as the ashing gas, a gas including at least one ofO₂ and CO₂.
 4. The apparatus according to claim 1, wherein the etchingprocess section, the ashing process section, and the silylation processsection are connected to a transfer chamber configured to maintain avacuum state therein and provided with a transfer mechanism therein,which transfers the substrate under a vacuum atmosphere among theetching process section, the ashing process section, and the silylationprocess section.
 5. The apparatus according to claim 1, wherein theetching process section and the ashing process section comprise aprocess chamber and a process gas supply system configured to supply theetching gas and the ashing gas into the process chamber.
 6. Theapparatus according to claim 1, wherein the etching process section, theashing process section, and the silylation process section comprise aprocess chamber and a process gas supply system configured to supply theetching gas, the ashing gas, and the silylation agent gas into theprocess chamber.
 7. The apparatus according to claim 1, wherein theetching target film comprises a siloxane or SiOC-based materialincluding alkyl groups as end groups.
 8. The apparatus according toclaim 1, wherein the silylation agent gas includes at least one of TMDS(1,1,3,3-Tetramethyldisilazane) and TMSDMA(Dimethylaminotrimethylsilane).
 9. A semiconductor device manufacturingapparatus comprising: an etching process section that uses an etchinggas to perform an etching process on an etching target film disposed ona substrate; an ashing process section that uses an ashing gas toperform an ashing process on an etching mask disposed on the etchingtarget film; a silylation process section that uses a silylation agentgas to perform a silylation process on the etching target film torecover damages of the etching target film inside a silylation chamber,the silylation process section being arranged to supply water vapor intothe silylation chamber to have portions of the etching target filmhaving the damages cause a reaction for absorbing moisture, whichfacilitates a silylation reaction; and a control section that controlsan operation of the apparatus, wherein the control section includes anon-transitory storage medium that stores a program for execution on acomputer to control the apparatus, which, when executed, controls theapparatus to conduct a sequence that comprises, operating the etchingprocess section to perform the etching process using the etching gas onthe etching target film, through a predetermined etching mask having acircuit pattern and disposed on the etching target film, to form agroove or a hole in the etching target film, operating the ashingprocess section to perform the ashing process using the ashing processon the predetermined etching mask to remove the predetermined etchingmask from the etching target film, after the etching process, andoperating the silylation process section to cause the reaction forabsorbing moisture by use of the water vapor and perform the silylationprocess using the silylation agent on an inner surface of the groove orthe hole of the etching target film to recover damages of the innersurface of the groove or the hole, after the ashing process.
 10. Theapparatus according to claim 9, wherein the silylation process sectioncomprises: a vacuum chamber configured to maintain a vacuum statetherein and serving as the silylation chamber; a vacuum-exhaust systemconnected to the vacuum chamber and equipped with a pressure adjustingmechanism; a gas supply system connected to the vacuum chamber andconfigured to supply the silylation agent gas into the vacuum chamber;and a hot plate disposed inside the vacuum chamber and configured tocontrol temperature of the substrate placed thereon.
 11. The apparatusaccording to claim 9, wherein the etching process section is configuredto etch, as the etching target film, a film comprising a siloxane orSiOC-based material including alkyl groups as end groups.
 12. Theapparatus according to claim 11, wherein the etching process section isconfigured to etch, as the etching target film, a MSQ(methyl-hydrogen-silsesquioxane) film.
 13. The apparatus according toclaim 11, wherein the silylation process section uses a gas, as asilylation agent gas, including at least one of TMDS(1,1,3,3-Tetramethyldisilazane) and TMSDMA(Dimethylaminotrimethylsilane).
 14. The apparatus according to claim 9,wherein the ashing process section is configured to perform ashing on amask, as the predetermined etching mask, including an SiCN film, ananti-reflective coating, and a resist film disposed in this order frombelow.
 15. The apparatus according to claim 14, wherein the ashingprocess uses a gas, as the ashing gas, including at least one of O₂ andCO₂.
 16. The apparatus according to claim 9, wherein the etching processsection, the ashing process section, and the silylation process sectionare connected to a transfer chamber configured to maintain a vacuumstate therein and equipped with a transfer mechanism therein, whichtransfers the substrate under a vacuum atmosphere among the etchingprocess section, the ashing process section, and the silylation processsection.
 17. The apparatus according to claim 9, wherein the etchingprocess section and the ashing process section comprise a common processchamber and a process gas supply system configured to selectively supplythe etching gas and the ashing gas into the common process chamber. 18.The apparatus according to claim 9, wherein the etching process section,the ashing process section, and the silylation process section comprisea common process chamber and a process gas supply system configured toselectively supply the etching gas, the ashing gas, and the silylationgas into the common process chamber.